The present invention relates to a drive circuit for producing scanning pulses to successively select the row conductors or column conductors of a planar type of display, and in particular an "active matrix" type of display, i.e. a display device based on liquid crystal display elements, for example, in which an individual switching element such as a thin-film transistor is provided for each display element, to control the transfer of data to the display element.
With prior art drive circuits for generating such scanning pulse signals, as will be described hereinafter in detail, the circuit configuration is usually based upon a set of master-slave flip-flops connected in series as a shift register. This enables the circuit to be made very simple, since the desired scanning pulses can be directly obtained from either the set of "master" outputs or the set of "slave" outputs of the shift register. However with such a circuit it is necessary to provide one master-slave flip-flop for each scanning pulse, i.e. to provide one master-slave flip-flop for each row of the display matrix in the case of a row drive circuit, or one master-slave flip-flop for each column of the matrix in the case of a column drive circuit. However if such a display is used in a miniature device such as an ultra-small television receiver, then it is desirable to reduce the circuit size as far as possible and in addition to minimize power consumption. It is therefore desirable to reduce the number of elements used to form peripheral circuits such as the row and column drive circuits, and the power consumed therein.